1. Field of the Invention
The present invention relates to a dual type BNC connector, and more particularly to a dual type BNC connector with an all metal shell.
2. Description of Related Art
The applicant or of the present invention has two patents about electric connectors. One is U.S. Pat. No. 6,676,443 entitled “ALL METAL SHELL BNC ELECTRICAL CONNECTOR”. As FIG. 1 shows, a connector has a metal shell 10 with at least a positioning hole 11 disposed therein and a BNC terminal 12 is accepted in each positioning hole 11. A metal cover 13 is attached on the bottom of the shell 10 so that the BNC terminals 12 and the lead wires extended from the rear ends of them are accepted in the space defined by the shell 10 and the metal cover 13. Therefore, the consuming rate of the transmission signal power of the BNC connector can be lowered, the interference resulting from the electromagnetic wave can be reduced so as to enhance the quality of the signal transmission of the BNC connector.
Another patent is U.S. Pat. No. 6,390,840 entitled “AUTO TERMINATION PCB MOUNT CONNECTOR”, in which insulators, a spring plate, conductive plate, resistor and metal jacket are installed in a casing. The metal jacket is pressed tightly from the receiving groove of the casing wall toward the inner side of the casing to contact and press the resistor against the conductive plate. A fixing element is associated at the outside of the casing; the connector is caused to be in conjunction with the printed circuit board by inserting the fixing element into a groove in a printed circuit board. The spring plate keeps contacting with the conductive plate in a normal state. The spring plate soon contacts with an inserting end of another connector and is separated from the conductive plate without contacting it if the inserting end of another connector is inserted. When the spring plate and the conductive plate contact with each other, an output signal transmitted to the spring plate can be transmitted back to the ground of the PC plate through the conductive plate, the resistor, the metal jacket, the casing and the fixing element so as to form a close circuit. The components of the connector according to the patent are few and the assembly thereof is easy. It can be inserted onto a PC plate, and the circuit can be allowed to have a better filtering function through the resistor so as to reduce the electromagnetic wave interference problem caused from the signal output from the spring plate and lower the loss of the power output.